Electric door operator



w. HAMILTON ELECTRIC DOOR OPERATOR Dec. 8, Y 1953 4 Sheets-Sheet 1 FiledNOV. 17, 1951 Ways Hom/Vf Dec. 8, 1953 l w. HAMILTON ELECTRIC DooROPERATOR 4 Sheets-Sheet 2 f Filed Nov. 17, 1951 5 m @y fw/n L@ 5. www Ew .M MW@ H 6. a f ,m/

Dec. 8, 1953 w. HAMILTON 2,651,945

ELECTRIC DOOR OPERATOR Filed Nov. 17, 1951 4 Sheets-Sheet 3 bi/V W f//ISatorveys 00a/R5 REVERS/N6 U) l/Ill Dec. 8, 1953 Filed Nov. 1'?, 1951Patented Dec. 8, 1953 UNITED STATES ori-*ICE 2,661,946 ELECTRIC noonOPERATOR Wallace Hamilton, Albanyj y., assiii ,o "il: solidatcdiCar-l-Heating Conipany,v Inc.; Albany; N. Y., a corporation of New York'Apblie'at'io'n ovember 17, 195i, seiai o, 256,864 7 Claims. (01;'acer-esi l o invention relates to door operators and particularly tothose which are actuated by electftY-- V,

At; the presenttirne; compressed air is generally us'ed for operatirigrtheldoors of buses and the like although in some cases such doors arehydrau'lially operated.1 But compressed air systems havelseveralinherent disadvantages. Despite regular precautions, the airlines and cylinders' eventaully' beeome clogged with dirt and, irffcold' weather, r,condensation and freezing of moisture' in thfleaii"Alines and cylinders causes Serious operating diiii'culties. Furthermore,piston' pacl'rirjlgfs` haveaj limited life and, in some instances, mustbe replaced very frequently. Because of thesek difliculties, correctvoperating adjustments are difficult' to maintain.` l

y Hydraulic systems lhave most of these, disadvantages plus severalothers. Loss of fluid due to leaks in the system'vcan seriously affectthe operation of thevehicles brakes and', occasionally a' leak spraysoillunder high pressure into tliej interior of a vehicle loaded withpassengers.

The principal object of my invention is toA proyide asafe, dependable,electrical unit for the control and' operationv of vehifclfer doors, VAlfurtherobject is to provide such a' device whichis adapted to: replacethe air and hydraulic cyl-` i'r'i'der'sinow being `used on buses tooperate the doorsV thereof although it may be used to operate hsftypes fdOOf'SI Irrthe drawingsf- ,A A, l p Y g; l is a planv view of the unit;Y Aigij 2 is a-front'elevation with portions broken away? e I FigfgBLisan enlarged, fragmentary plan View, partially in` section-of a detail;

Fig'. 4fis an enlarged, fragmentary planpv'iew of another detailshowing' the rel'ativeposition Vof the 'partswhen the` doors areI in'open' position; Fig. 5 i'sy a frontv elevation view of the detailshwirih-Fia e A l Fig', 6 isa'section'ofjFig. 5 in the plane E B';

grams showing tlie variousl switches andv circuits whieh exisewhen-the'doors are ih various posi-v tions; and

Figs; 14,15, i6, 1'7-y and 18; are" diagrammatic lLisjthehase te, whichvarious eieinenis qffiieiV unit are' attached' 2' `is an electric'mot/or khaving opposiiejsides by ,means of, i'v'h'ieh ihelmeporuissupported ir`1',lortcliets,.5 and E. y Secured to4 each eri'd ofthemotor shaft' 1 is a Aworrnho'r screwl., only' one. ofwhicliis`s'fliown,,which cooperate with bauwndts, 11 te, feritiareveieibie 'driving mechanism' firhatI to'sayth m'tpimay, drive theI'iut'sloe the wl ms', or th ,Iito'r may be driven by yforce applied@either ofthe haisz ih a direction' ,Wh'ieh ,wi111, nieve i6v'ii'ahgiiiuiina uy er its associated w Thenuts Il. are/fixed Ato theshafts 9' and ylflw ich,actuate the doors'. as folfY lows: thefreeendsof the shafts 9v and It are loi'frcate'd, as shown at |2 andl and, haveaol-,- jistablelinlis I Iland l5 piyotally securedthereto by p .YI,Il"i`ia,rl1d'., Il, respectively. The links I4 and l5' are pivotallysecuredtovthe arms li8 and ,9

respectively,wh'icl`1`,in, turn"I are clamped'A l to the vertical shafts2'0 and 2l which actuate the doors 2.2 'and-v .,v.

1a oidertoioek thev adore ih chased positien I prox/idea ieggije `whichhis" aeiuajied by, the yshaft in and which' W111i he described ih'cd'nn'eeiihf with Fi as, 4, eiland one ieg 24 of the toggieis secured infiiied pivotal' relation to the baseand fnotgi, lis'shown atj 2 5inFigs. f1 and 5;` Yand the et er ,ieg 6,l the iengthef Whiehrh'ay beadiuste'd' by means of thelthre'add rdl, is pitictjd ali-128' to theshaftV lll by means 0f th'eIpln iztha Y'Ol'ilflcl'l's'th lklthelto. i,AmX'lhQ-.b 555m eletfglli ghafving the paie- :i6` thereof and alU-shaped frame 36'., 'attachedA to the' other peiewiih its free ende16e sidespi ihepoieso, forming a subies'ed magnetic eireuit with thetoggle 1y members 2,4,and 26Jwhen the k'nee'Lis in close pQXty tth'pl 30andfSid toggle 's'alnst butnot Iufte, s raigh't.' Thus, when themagfnetis ler izedgitwill Serve, to hold the togglein straightpehditioh aridthus ioek the itsyairh dijrs'zivny los'ed position. c `Secured kto the,hase 1is a relay, represented 1i; bizih'egmmeieiiz and, which. when dvuiesiihi seperate. switches the with Eig jllgllinclusye, m33 representsA al 'roloclv tdwhichdelectrical i Y .eefploperlh @tonneau electri-` lliil; vario s .cqr ltrol.elements of the device are come@ ed. The various`circuits willbe ex,-

plained'heIQWand the' manner in which the varidus,aiit'inaticswitchesereconnected in `these circuits W1ll,-al'so,beexplained, R g first,howevento Figs. l and 2, 34

operating" element 35 which is contacted by the ,11' Qf which Will Deexplained below/11.1. con-` pin I1, or other means moving with shaft 3,when the doors are open. 36 is a closing limit switch having anoperating element 3l (see Figs. 4 and 5) which is actuated by the pinI6, or other means moving with shaft I0, when the doors are closed. 36is another switch which is actuated by the pin when the doors areclosed. 38 is an opening braking switch having an operating element 39which is actuated by the machine screw 39' in leg 24 of the toggle whenthe doors are almost open. The screw 39 may be adjusted when theoperator is installed so that switch 38 is actuated at precisely theproper time.

Referring now to Figs. '7-l3, inclusive, in connection with Figs. 14-18,inclusive, Fig. 7 shows the position of the various switches when thedoors are in closed position. 40 is the manually controlled operatingswitch; 4| is the battery; 42 is the coil of relay 32, which, whenenergized, moves the switches 43, 44 and 45 to the left; 46 representsthe armature of the motor 2 having the series eld 41 and the shunt eld48; 43 is the coil of the electromagnet 29 which locks the doors inclosed position, and which is of comparatively high resistance; is adiagrammatic .2

showing of the closing limit switch 36; 5| is a similar showing of theopening braking switch 38; 52 is the braking resistor which has acomparatively low resistance; 53 is the closing speed resistor; 54 isthe relay holding resistor; 55 is a current limiting resistor; and 56 isa diagrammatic showing of the opening limit switch.

All of the circuit forming means are shown in solid outline, but theparticular circuits which are established from time to time are shown indotted outline, and the direction of current flow therein is indicatedby the arrows.

When the doors are in closed position, the switches and circuits are asshown in Fig. '7. The switch 48 is open, the relay coil 42 is notenergized, and the switches 43, 44 and 45 controlled thereby are in thepositions shown in this figure. In this position, current from thebattery 4| flows through the switch 43, the coil 49 of the lockingelectromagnet, the armature 46 of the motor, the closing speed resistor53, the switch 45, the series iield 4| and the shunt field 48 of themotor, and back to the battery. Since the resistance of the coil of theelectromagnet which locks the doors in closed position is comparativelyhigh, as

pointed out above, and considerably greater than the balance of thecircuit, the current flowing through the circuit is suiiicient toenergize the coil of the electromagnet but is not sufficient to operatethe motor.

Referring now to Fig. 3, when the control switch 40 is closed, the relaycoil 42 is energized and the switches 43, 44 and 45 are thrown into theposition here shown, and the following circuits are then established:From battery 4| through the switch 40, the relay coil 42, and back tothe battery. At the same time, another circuit is established from thebattery 4| through switch 43, opening limit switch 56, opening brakingswitch 5|, the armature 46 of the motor, switch 45, the series eldwinding 4'| and back to the battery. A third circuit is also establishedthrough the switch 44, the shunt held winding 48 of the motor, andthence to the battery. It will be noted that the coil 49 of theelectromagnet which locks the doors in closed position is nowdeenergized by the movement of the switch 43 to the left, and is shuntedby the release of the closed limit switch.

As the doors approach their fully open position, circuits areestablished as shown in Fig. 9.

CTI

The opening movement of the doors automatically moves the openingbraking switch 5| to the position shown in Fig. 9. When the doors arealmost open, the relay coil 42 remains energized, and the followingcircuits are established: From the batt-ery through the switch 43,opening limit switch 5E, switch 44, the shunt iield winding 48 of themotor, and baci'. to the battery. Two other circuits are simultaneouslyestablished, one of which includes the current limiting resistor 55, theopening braking switch 5| the opening braking resistor 52, the seriesiield 47 of the motor, and back to the battery; and the other circuitthrough the armature 45 of the motor, the switch 45 and the series heldwinding 41 back to the battery. In this position, it will be noted thatthe circuit through the shunt field 48 is the same as in 8. The currentflow through the rest of the motor circuit however, passes through theresistor 55, the armature 46 of the motor, the series eld 4l 'to thecattery and also through the opening braking switch 5|, the resistor 52,and the eld 4l to the battery, thus partially shunting the armature 46.The armature current is thus greatly reduced with respect to that of theiields and causes the motor to rotate at a much slower speed. Thekinetic energy of the moving doors then drives the motor which acts likea generator. The current generated by this driving action is dissipatedin the form of heat in the resistor E2 in the circuit which shunts thearmature, and the motor exercises a braking effect which prevents thedoors from slamming as they reach the fully open position. Since theresistance of the resistor 52 isv comparatively low, the current fromthe battery is limited by the action of the resistor 55. The resistancesof the resistors 52 and 55 are interdependent and must be such that themotor will stiil operate slowly towards the opening position in theevent some obstacle slows up the opening doors.

When the doors reach the fully open position, the opening limit switch56 is automatically opened by the movement of the doors and brakes thecircuit through the motor, leaving only the relay coil 42 in energizedcondition. The circuits then are as shown in Fig. 10. In order to closethe doors, the control switch 4i) is opened as shown in Fig. 11. Thisdeenergizes the relay coil 42, the switches 43, 44 and 45 reassume theiroriginal positions, and the following circuits are established: From thebattery through switch 43, closing limit switch 50, armature 45, but ina direction opposite the direction in which the current flowstherethrough during the door opening movement as shown in Fig. 8,through the resistor 53, switch 45, series iield 41 and back to thebattery. Another circuit is established through the switch 44 andthrough the shunt winding 43. Because the resistor 53 is now in serieswith the armature and the series field of the motor, the motor operatesat a slower rate than during the door opening movement, thereby causing'the doors to close at a somewhat slower speed than that at which theyopen. When the doors reach closed position, the closing limit switchii'is automatically moved from the position shown in 'Fig'. 11 totheposition shown in Fig. '7, thereby energizing the high resistance coil49 of the electromagnet which locks the doors in closed position andreestablishes the circuit shown in Fig. '7.

The adjacent edges 51 and 58 of doorsof the type shown in Figs. 11i-18,inclusive, are usually fitted with so called sensitive edges comprisingl`swritches encased in rubber tubes which will close Vwhen either of thetubes is deformed by pressure applied; tothe outsideof the iii-tbc. Thedoors shown. 'm the last mentioned figures areto be mideafstood as beingequipped with suchedges,

the switches 59 and B0- Fifg.-

are to be understood asV diagrammaticallly representing the switches inthe door' edges.- Either one orl both ed these: switches: may te closedby pressure eaerted on the edge of the door by an obstacle: en-

countered the closing thereof.- The-switch-Bl,

as shown-- F'igsi 71412, inclusive, isadiagramshowing of' the switch 345Figsg l? and 2'-, and the .switch 62 may be associated therewith or withthe closed limitsvviltcirl 5t so--that'- theyare automatically actuatedto the positions shown` i-n Fig.v '71' when; the doors are closed. ifthere isno pressure against the edgesof the door, both switches.5Fl-andi BB1-aire normally open.

Assuming' that pressurel is appl-redI tol-the edge of theldoor withwhich: the-switch 5i) is; associe ated, this switch- Will close, asshow-n in- Flfg. 112; and., initially, establish a circuit fromthebatteryf' through thei relay coil 42T which will energize the-.relay andcauseithe-switches- 431, M1 andi-'Iiix to movetothe lett into: theposition show-n in` Fig. Thi'slwi-ll; establish avrel'ay circuit (showniii-solid outline only tol avoid con-fusion)l through the rinotor andcause'l the doorsi tostart` opening. The mo'vementl of the. switches $31and- 4'4 however, to the position shown ini Fig; 123, establishes a ciiTcuit from the. battery throng-h1 the switch the opening limit.stvilicliv 563 theaV resistor 54, coil i12 of the relay, and1 back tuLtliei battery; itl bei-ng appareilt- 'that the' circuit: through-- the:motor is the: door-opening circuit similar tothat shown irrl'ig. Whenthel door-s1 reach the fullyopen position,- they opening-'limitswitch45. isautomatically -openedi wl-iiclfrdeenergizes the. relay',- causesthe switches-43,. 4l'. and 4'5 tomove intothe pesi:- tionshownin- Figulll, andi the doors sta-rt closing. When closed',v the' closing limitswitch te automatically opens;- andi theV circuitsf shcwn'- in Eig; '71"are: reestablishedli In addition-to actingI as a clcsingrliimitsiti-tong the' 501 may' also function to` operate sig xialliglht`torletthe operator know.' whenthe doors are' fully'clb'sedtherconducto'ii G3i runningtothe signal light (not sho-wm? and` a`conductor (not shownrlf returning'.l fromfthe? signal; rlig-ht to thebattery.

The switch' 62', which' is" automatically actuated simultaneously with.the.- switch 6l andthe closed limit'switch, may be used through theconductcr 66 to control` ani interlock device (not shown), l

suchasa relay or magnetic air` valve, control-- lingy the power supplyof thefvehicleand its'brales sri-that. no power will beavailableawhenthe' vehd clefs brakesare setA unless the doors are` fully closed. Y

Theiconductor 64 extends from: one terminalof theswitch.'Y 611 to thesensitives edges, as sl'iclwn im Figs. 12;. and the codnuctcr.-y 551transfers any by magnetic means ofi-ly',- Iiri the event dt a failure,there would beno current g through the loch coi-li, and' the doorsanthenbe opened manually,- since the ball nut and screw are reversible action.Alisa the case'v of van emergency;- the doors could be openednan-ualllyby v a passenger after' operatinganemergency switch- (not shown), whichwould merely dis'coi-le nectthe source ofbattery volta-ge totheeperatoi.

From'- the foregoing,- itwiiibe clear that i have provided! arrelectrically* operated unitary device which may be employed for openingand closing doors ot elevators, buses, trains the like and which, exceptfor` the manually op 3ated-'- co trol switch 4'0, is acompact unit fromWh chi cendre tors may be'- runto the' various auxiliary devices iti-'sdesi-reet to# be operated thereby.-

While E have described inventienin itsvi prefeiliied embodiment, it toebei uln'derstood that the words which have used are-wordS-o descriptionrather than oi?- limitation and tha-tchanges, within the pui-viewof theappended claiin's,-1tay be? made'- W'thout depar-i'iIg1-f-ii'ornA` thetrue scope and spi-rit of my in-ve-ition itsibroaider aspcts Wha-t1-claimis door opera-tor, comprising a rever-sible electric meter; a-Worin-connected t'oth sh it ci said nietor and" dr-iven'-` tlfiereby{a-Lball nut c'o' operating Wi'tlr sail-li worin,- wli "soy, said worin' andnut form are'versi-bledriving inecl-iariisiir; means operativelyconnected'- tof said nutV adapted' to be operatively connected-toadoersha-f-t for turningthe-saine as said nut'- moves onsaidf ivorm-- atogglehavi-ngftlief-ree-endf of( @ne leg thereof hel'd in xd pivotalrelatibn motor, the free end of the other leg-pivot yy' nectedi ta saidnut, and-being only slightly bent at' the-linee when saidiiut-l isli-'nidoorrclcsediposiition; an`v electiornagnet having' it'seldl in' cl'cseproximity te sa-id togglewheni said5 nut isL in doorn closed position;whereby-when energizedi-saiii magnet will hold1 said tcggl'eapproximately straight and-'lock'said door Ain closedipositibni andelectric circuit forming"V means, inclue" v' said electromagnet and: aswitch automatically actu` ated by the door-closing movement said operarter-Whensaidi door is" substantially closed, for closing saidcircuit-and energizing' said magnet toilocli said door in closedposition:

ZiA door operator adapted to open and" close a4 pair of doors' andIcomprising" a reversible elec;- tric motor right and .left hand wormsconnected', respectively, tof the opposite" ends of the shaft of saidmotor andz driven" thereby; a pair ci" bali nuts, one cooperating with:each' of" saidy worms, whereby each' of' said'l Worms" and its.cooperating nut forms a' reversible driving" inechanisrn;y ,meansoperatively connected to each" ofl saidr nuts and adapted 'to'be'operatively connected to the' shafts of said doors forv simultaneously'turningA the' sarde to openY andi closev said doors as said nuts nieve'end'oi` one ofitlieleg'sthereof held in'x'e'd pi'vtal relationto's'a'idi motor; the free end" of the other leg pivotally connected toone of said nuts, and being only slightly bent at the knee when saidnuts are in doors-closed positions; an electromagnet having its eld inclose proximity to the knee of said toggle when said nuts are indoorsclosed positions; whereby, when energized, said magnet will holdsaid toggle approximately straight and lock said doors in closedposition; and electric circuit forming means, including saidelectromagnet and a switch automatically actuated by the door closingmovement of said operator when said doors are substantially closed, forclosing said circuit and energizing said magnet to lock said doors inclosed position.

3. In a door operator, the combination with a shaft secured to saiddoor, and about the axis of which, said door is swingable to effect anopening and closing thereof; of a reversible electric motor having shuntand series fields; a worm connected to the shaft of said motor anddriven thereby; a ball nut cooperating with said worm, whereby said wormand nut form a reversible driving mechanism; means operativelyconnecting said shaft to said nut; a source of power; a manuallycontrolled switch; a relay energized from said source of power when saidcontrol switch is closed; means, including an electromagnet normallyenergized when said door is closed for locking said door in closedposition;

a rst switch actuated by said relay, when energized, for deenergizingsaid electromagnet to unlock said door; a second switch actuated by saidrelay, when energized, for connecting said motor, including both eldsthereof, to said source of power to effect an opening movement of saiddoor; and a third switch automatically actuated by the door-openingmovement of said operator when said door is near its fully open positionfor closing a shunt circuit around the armature of said motor, wherebyto reduce the speed of said motor by reducing the current fiowingthrough the armature thereof while maintaining the current flowingthrough said fields substantially constant; whereby, said motor willfUnCtOn as a brake and prevent said door from slamming open.

4. The structure set forth in claim 3 together' with a fourth switchactuated by the door-opening mechanism when said door is fully openedfor automatically opening the circuit from said source of power throughsaid motor.

5. In a door operator; the combination with a pair of doors; of means onwhich said doors are mounted to move towards and away from each other toeffect a closing and opening thereof; a reversible electric motor havingshunt and series fields; a right hand worm connected to one end of theshaft of said motor, and a left hand worm connected to the other endthereof; a ball nut cooperating with each of said worms and formingtherewith reversible driving mechanisms; means operatively connectingsaid nuts to said doors; a source of power; a manually controlledswitch; a relay energized from said source of power when said controlswitch is closed; means, including an electromagnet normally energizedwhen said doors are closed for locking them in closed position; a firstswitch actuated by said relay, when energized, for deyenergizing saidelectromagnet to unlock said '1" doors; a second switch actuated by saidrelay, when energized, for connecting said motor, including both fieldsthereof, to said source of power to effect an opening movement of saiddoors; and a third switch automatically actuated by the door-openingmovement of said operator when said doors are near their fully openposition for closing a shunt circuit around the armature of said motorWhile maintaining the current flowing through said fields substantiallyconstant; whereby the speed of said motor will be reduced and said motorwill function as a brake and prevent said doors from slamming open.

6. The structure set forth in claim 5 together with a fourth switchactuated by the door-opening mechanism when said door is substantiallyfully opened for automatically opening the circuit from said source ofpower through said motor.

7. In a door operator, the combination with a. shaft secured to saiddoor, and about the axis of which, said door is swingable to effect anopening and closing thereof; of a reversible electric motor having shuntand series fields; a worm connected to the shaft of said motor anddriven thereby; a ball nut cooperating with said worm, whereby said wormand nut form a reversible driving mechanism; means operativelyconnecting said shaft to said nut; a source of power; a manuallycontrolled switch; a relay energized from said source of power when saidcontrol switch is closed; means, including an electromagnet normallyenergized when said door is closed for locking said door in closedposition; a first switch actuated by said relay, when energized, fordeenergizing said electromagnet to unlock said door; a second switchactuated by said relay, when energized, for connecting said motor,including both elds thereof, to said source of power to effect anopening movement of said door a third switch automatically actuated bythe door-opening movement of saidoperator when said door is near itsfully open position for closing a shunt circuit around the ,armature ofsaid motor, whereby to reduce the speed of said motor by reducing thecurrent flowing through the armature thereof While maintaining thecurrent flowing through said fields substantially constant; whereby,said motor will function as a brake and prevent said door from slammingopen; and means for adjusting the time at which said third switch willbe actuated by the door-opening movement of said operator.

WALLACE HAMILTON.

References Cited in the le of this patent` UNITED STATES PATENTS lNumber Name Date 1,783,354 Ainsworth Dec. 2, 1930 1,839,232 LapatoffJan. 5, 1932 2,053,172 Young Sept. 1, 1936 2,075,000 McCloud Mar. 23,1937 2,476,111 Opalek July 12, `1949 2,558,032 Andrews June 26, 19512,572,785 Vaughn Oct. 23, 1951 2,583,662 Noble Jan. 29, 1952

